Gas-operated firearm



C. A. NELSON.

GAS OPERATED FIREARM.

APPLICATION FILED SEPT. 21. 1918.

1,3 8, 79, Patented Aug. 30, 1921.

l a I I WW/ k W/ A TTORNEY UNITED STATES PATENT OFFICE.

CHARLES A. NELSON, OF U'lICA, NEW YORK, ASSIGNOR TO SAVAGE ARMSCORPORA-. TION, A CORPORATION OF DELAWARE.

GAS-OPERATED FIREARM.

Specification of Letters Patent.

Patented Aug. so, 1921.,

Application flied September 21, 1918. Serial No. 255,058.

To all whom it may concern:

Be it known that I, CHARLES A. NELSON, United States citizen, residingin Utica, New York, have invented the following described Improvementsin Gas-Operated Firearms.

The invention relates to the connection between the muzzle and gascylinder in gas operated fire arms and consists in the structure andorganlzation of the several parts and functions as hereinafter describedwhereby the said connection is stronger and more easily and accuratelymanufactured and assembled, at the same time providing for the readyadjustment of the gas transmission, and whereby also other advantagesare obtained as will be hereinafter made apparent to those skilled inthis art.

In the accompanying drawings Figure 1 is a longitudinal section througha portion of a gun showing the gas cylinder and adjacent parts includingthe gas connection constructed according to this invention;

Fig. 2 is a bottom plan of Fig. 1;

Fig. 3 a cross section through the gas connection;

Figs. 4 and 5 are details of the gland; and

Fig. 6 of the regulator cup.

In the drawings the gun barrel is marked 1 and indicated as containedwithin a ribbed heat radiator 2, the latter being surrounded by a casing3. The gas cylinder marked 4 is within the casing, being parallel withthe gun barrel,;and its gas-operated piston 5 is shown in its forwardposition. It will be understood that the pressure of the muzzle gasestransmitted through the connection fit tings about to be described, actsupon this piston to effect the various functions of the arm.

The said gas connection comprises two fittings, first a fitting 6 havingan interlor space which may be termed the gas chamber and a band 7 whichencircles and fits snugly over the gun barrel at a point near the muzzle thereof where the vent port 8 is bored in the latter. At its rearside the gas chamber of fitting 6 is formed with a tubularexternally-threaded boss 9 which forms the head of the gas cylinder atwhen the latter is screwed thereon. .The lower end of the gas chamber isopen and internally threaded to receive the second fitting 10 which maybe termed the gas gland, the upper or inner end of which is providedwith a tubular tapered nipple 11 adapted to protrude from the gaschamber into the vent port 8 which is correspondingly tapered so thatwhen the gland is screwed home in the chamber the nipple seats tightlyupon said port making a gastight joint therewith and the pressure thusexerted serves also to bind and clamp the band 7 to the muzzle. Inasmuchas the gas chamber is in one piece' with the muzzle band and the glandis confined within it, it will be apparent that the connection isexceptionally rigid and secure so long as the gland is protected fromunscrewing. Its internal location, within the gas chamber, is aprotection in this respect but fur ther security is provided by makingthe lower end or screw head of the gland hexagonal or multi-sided andwide enough so that it overlaps the boss 9 whereby the gas cylinder 4can be screwed up on the boss far enough to engage one of the flat sidesof the head or at least close enough to it to prevent unscrewing underthe effects of vibration. It should be observed moreover that by virtueof the described arrangement of exterior and interior fittings, thejoint-making and clamping pressure is produced by the screwthreadedengagement of parts of relativelyv large diameter and ample sectionpermitting the use of adequately fine threads with a maximum strength.

The gas gland fitting 10 is hollow and provided with a number ofapertures 12, one of which is always in registry with the hole throughthe boss 9 when a flat side of the hexagonal head is engaged by the gascylinder 4: thus providing a gas flow passage from the port 8 to the gascylinder. The regulating cup 13 is screwed into the open end of thegland fitting so that its upper or inner end occupies an annular groovein the upper part of the gland. Its cylindrical wall is provided with aseries of ports 14 of graded diameter, any one of which can be broughtinto registry with the ports leading through the gland and boss 9 forrestricting or regulating the gas flow accordingly. The lower end orhead of the cup 13 is provided with cross slots 15 to receive the toolby which the cup can be turned in the gland to accomplish thisadjustment. The tool-a gun screw-driveris normall held by one of thecross slots with its flexib e handle 16 formed with, a stud 17 engagedin a hole on the underside of the caslng 3, from which it may readily beremoved to regulate the gas cup or for use elsewhere.

The foregoing description of the preferred form of this invention willsufficiently illustrate the principle thereof and it will be apparentthat the same can be embodied in various forms and applied in variousways to secure the practical advantages of the structure shown andespecially the advantage of the large diameter threads for securing theband to the barrel and forming the gastight joint therewith.

Claims:

1. In gas operated fire arms, a gas connection between the muzzle andgas cylinder including two fittings one of which is connected to thecylinder and encircles the muzzle and the other ofwhich in. itself formsa gastight connection between the first fitting and the muzzle.

2. The gas connection of claim 1 in which the second fitting is screwthreaded into a gatrt of relatively wide diameter of the first 't in 3.The gas connection of claim 1 in which the first fitting includes a gaschamber and the second is contained Within said chamber.

4. The as connection of claim 1 in which the secon fitting has a screwhead locked against unscrewing by engagement with the gas cylinder.

5. In a gas operated fire arm, a gas connection between the muzzle andgas cylinder comprising a one-piece muzzle band and gas chamber and ascrew-threaded gland member within the gas chamber formin a gastightconnection with the muzzle an clamping the band thereto.

6. In a gas operated fire arm, tion between the muzzle and gas cylindercomprising a one-piece muzzle band and gas chamber, a gas gland thereinand a regulator cupwithin the gas gland.

' In. testimony whereof, I have signed this specification.

CHARLES A. NELSON.

a gas (30111180-

